1. Colloid versus Crystalloid in Hypovolemic Shock Controversy www.anaesthesia.co.in email: anaesthesia.co.in@gmail.com

2. Crystalloids Fluids comprised of water and electrolytes or simple crystals Volume of distribution- intravascular,interstitial space Volume - 3 : 1 Examples Ringer’s lactate, hypertonic saline, normal saline

3. Colloid High molecular weight substances Volume of distribution -intravascular space Volume – 1: 1 Exert colloid osmotic pressure Costly Examples HES, Haemaccel, Albumin, Dextran

4. CrystalloidsColloids Intravascular vol effect-Better Interstitial vol. effectBetter- Pulmonary edemaSimilar potential Peripheral edemaCommonUncommon ReactionsAbsentCommon CostInexpensiveExpensive

5. Albumin 5%, 20% and 25% Half life – 16 hr Colloidal osmotic pressure - (25%) - 70 mmHg  plasma volume by 400-500 ml Vol. expansion occur at expense of interstitial fluid so 25% should not be used for resuscitation Side effects – allergic reaction

6. Haemaccel Synthetic colloid Degraded gelatin Concentration - 3.5% Half life – 2-3 hr Dose – 20 ml/kg/day Osmotic pressure – 300 mmHg Side effects – anaphylaxis, coagulation interference (high dose)

7. M.wt (KD)Conc.I.V.stay (hrs) Dose (ml/kg/day) 2003%1-260 2006%3-430 20010%4-820 4506%6-820 Hydroxyethyl starch

8. Crystalloids vs Colloids Proponents of colloid fluid Resuscitation crystalloid solution dilutes plasma proteins Reduction of plasma oncotic pressure Interstitial pulmonary edema Requires smaller initial volume, generate prolonged  in circulating plasma volume Isotonic crystalloid – must be infused at least three fold greater volumes- to achieve comparable plasma expansion and hemodynamic stability

9. Proponents of crystalloid solution Additional cost and potential risk of colloids Removal of colloids- requires longer period than crystalloids in burn and major surgical patients Sepsis, ARDS, surgical trauma,  capillary permeability  leak  edema Coagulopathy – Dextran, HES >20 ml/kg  ionised calcium albumin Impaired cross-matching – Dextran Osmotic diuresis  LMW dextran

11. Crystalloid vs. Colloids in fluid resuscitation: A systematic review Peter Choi et al (1999) RCT 814 pts. No apparent difference in pulmonary edema, mortality or length of stay between isotonic crystalloid and colloid resuscitation Crystalloid resuscitation- lower mortality in trauma patients Fluid resuscitation with colloid or crystalloid - critically ill patients Schierhout G et al, 1998 Metanalysis 26 RCTs 1622 pts. Increased risk for death of 4% with colloid for resuscitation Cochrane review 30 RCTs 1419 pts. Risk for death higher in albumin treated gp. Vs. albumin + crystalloid gp.

12. BMJ 1998;317(7153):23 5-240 RCT Multicenter 42 pts. No statistically significant difference b/w crystalloid and albumin gps. w.r.t. days on mechanical ventilation, oxygenation failure, length of ICU stay and mortality rate in critically ill pts. with shock SAFE trial N Engl J Med 2004;350(22):2247- 2256 RCT 6997 pts. No difference b/w albumin and saline w.r.t mortality rate, days of stay in ICU/ hospital/ ventilation

13. What to do ? According to literature: 1.Crystalloids - first preference-when available(NS,R/L) 2.Colloids –Keeping in view of adverse effects and dosage,colloids can be given with crystalloids 3.Avoid albumin as resuscitative fluid